Idle Speed Control System

Engine Control Module (ECM) is programmed with engine idle speed values. Idle air control system provides a stable idle speed when engine is cold and idle speed decreases due to electrical load.

An input signal is delivered to ECM, indicating when high electrical output is required. Input signal is delivered when items such as rear window defroster, headlights, etc. are turned on. The ECM uses input signal along with other various input signals to maintain proper idle speed by controlling Idle Air Control (IAC) valve located on air intake system.